【摘要】 以兰州红咀寺剖面为例 ,以 2 cm的间隔采样 ,进行了碳酸盐含量的测定 ,获得数据 892个 ,与其它古气候指标 (磁化率、有机碳总量 )进行对比后揭示了该地区近 3 0× 10 3 a来气候变化的频率及突变事件。3 0× 10 3 a以来主要可以分为 4个阶段 :暖湿期(3 3× 10 3 ～ 40× 10 3 a B.P.)、凉偏干期 (3 0× 10 3 ～ 2 7× 10 3 a B.P.)、寒冷干燥期 (2 7× 10 3 ～ 10× 10 3 a B.P.)、暖湿期 (10× 10 3 ～ 3× 10 3 a B.P.) ,各阶段中气候快速变化明显更多还原

【Abstract】 Carbonate is one of the common chemical components in Quaternary sedimentary rocks.The content in loess has the significance of palaeo climate.Taking Hongzuisi loess section in Lanzhou as an example,sampling in 2 cm intervals,and testing the w (CaCO 3) as mass fraction of carbonate in loess,gaining 892 datum,the paper finds that the 17 m high resolution records a detailed history of palaeo climate change since 30×10 3 a in Lanzhou.According to the curve of the w (CaCO 3),the palaeo climate in the area can be divided into 4 main stages:33×10 3-30×10 3 a B.P.,when the w (CaCO 3) is falling,and the climate is cold and dry at the beginning,but the climate is warm and wet at the end of this stage;30×10 3-27×10 3 a B.P.,when the w (CaCO 3) is higher,the biggest value is 19% at about 28×10 3 a B.P.,corresponding to the cold and dry;27×10 3-10×10 3 a B.P.,when the w (CaCO 3) is stable,but there are two big fluctuations in 14×10 3-10×10 3 a B.P.,and the w (CaCO 3) reachs the highest.The climate becomes colder and dryer;Younger Dryas Event 10×10 3-3×10 3 a B.P.,the big warm period in Holocene,when the w (CaCO 3) fluctuates frequently and the climate is warm as a whole in this period.更多还原